(a) Field of the Invention
The present invention relates to a thin film transistor array panel and a manufacturing method thereof.
(b) Description of the Related Art
Generally, a thin film transistor array (“TFT”) panel for a liquid crystal display (“LCD”) or an electro-luminescence (“EL”) display is used as a circuit board for driving the respective pixels in an independent manner. The TFT array panel includes a scanning signal wire or a gate wire transmitting scanning signals, an image signal wire or a data wire transmitting image signals, TFTs connected to the gate and the data wire, pixel electrodes connected to the TFTs, a gate insulating layer covering the gate wire for insulation, and a protective layer covering the TFTs and the data wire for insulation. The TFT includes a gate electrode, which is a part of the gate wire, a semiconductor layer forming a channel, source and drain electrodes, which are parts of the data wire, a gate insulating layer, and a protective layer. The TFT is a switching element for transmitting the image signals from the data wire to the pixel electrode in response to the scanning signals from the gate wire.
The TFT array panel has been extensively used for the LCD. As large-sized high-resolution LCDs have been developed, the gate and the data wires become to have significantly elongated length but gradually narrowed width. Accordingly, signal distortion due to the increase in the resistance of the wires and in various parasitic capacitances becomes to be a critical problem. In this connection, silver (Ag) wire come to the attention because it has good contact characteristic with an amorphous silicon layer and having low resistivity compared with a conventionally-used aluminum alloy wire.
However, silver exhibits poor adhesiveness to a glass substrate or a silicon layer. The poor adhesiveness frequently causes the defect such as the looseness or detachment of the silver thin films during the subsequent processes such as cleaning, which results in the disconnection of the wire. Furthermore, silver may be easily damaged by dry etch of the silicon nitride insulating layer.